NVO3 is a technology for implementing network virtualization. A physical network can be virtualized using the NVO3 technology such that one physical network can be shared by different tenants, where data flows of the tenants are segregated from each other, and Internet Protocols (IPs) in virtual networks (VNs) used by different tenants can be the same, which is equivalent to that each tenant uses the physical network independently.
In a network using the NVO3 technology, each tenant generally includes one or more VNs, where layer 2 (a data link layer) interworking between tenant end systems (TESs) in each VN can be implemented using an NVO3 network, and interworking between TESs in different VNs is implemented using layer 3 network (a network layer). A network virtualization edge (NVE) is a VN edge device of an NVO3 network, and is responsible for flow forwarding between different TESs in each VN, NVO3 tunnel encapsulation and decapsulation, and other processing.
At present, each layer 3 data flow to be transmitted across subnets in an NVO3 network generally needs to be forwarded using a centralized layer 3 gateway. However, if each layer 3 data flow to be transmitted across subnets is forwarded using a centralized layer 3 gateway, a detour may be caused on a forwarding path of the layer 3 data flow, and a forwarding bottleneck may be easily formed at the centralized layer 3 gateway, thereby affecting efficiency of packet forwarding.